airborne diseases

1. Dr. Rahul Netragaonkar
Professor
Community Medicine
Zydus Medical College, Dahod
Influenza, Bird Flu, Swine
Flu & SARS

7. INFLUENZA

8. • An acute respiratory
tract infection.
•Caused by the. influenza
virus 3 types A, B & C
•All known pandemics
caused by Type A strain.

10. EPIDEMIOLOGY
• Truly an international disease.
• For every 10 to 15 years pandemic
occur due to antigenic variation.
• 1918 - Spanish influenza.
• 1957 - Asian Influenza
• 1968 - Hong Kong

11. • 21 million people died worldwide
mostly due to secondary bacterial
pneumonia.
Epidemics occur between pandemics
at intervals.
2 - 3 years - Influenza A
4 - 7 years - Influenza B

12. UNIQUE FEATURES OF
INFLUENZA EPIDEMIC
•Large number of subclinical cases.
•High proportion of susceptible population.
•Short duration of immunity.
• Suddenness
• Speed and ease which they spread.
• Short incubation period.

13. • All contribute to its rapid spread.
• At present 3 types are circulating in
the world A(H1,N1) A(H2,N2) B virus.
• WHO global surveillance identified
human infection with a new influenza virus
called A (H5,N1) in Hong Kong in mid 1957

14. Bird flu (Avian Influenza)
• Is a viral infection that infect birds.
• H5N1 is the most common form of bird flu.
• It’s deadly to birds and can easily affect
humans and other animals that come in
contact with a carrier.
• range of responses from almost no signs of
the disease to very high mortality.
• The incubation period ( 3 to 7 days).

15. • In HongKong H5 N1 strain infected
human causing 18 cases including 6 deaths.
• In mid 2003 virus caused largest and
most severe out breaks in poultry on record.
• Since there over 100 cases have been
laboratory conformed in 4 Asian countries
named, Indonesia, Thailand, Cambodia,
Vietnam more than half people died.

16. Avian Influenza Incidence Tracking Map, February
27th, 2006: 45 Countries Have Bird Flu.

24. Mode of transmission
• Direct or indirect contact with infected live
or dead poultry.
• No evidence – cooked food.
• No human to human transmission.
• But mutation – human to human transmission.
• Host :
•Usually chickens, ducks, and turkeys.
• Environmental :
•Usually winter, Overcrowding.

25. Symptoms
• High grade fever >38 deg. C
• Cough/sore throat
• Diarrhea, vomiting, abdominal pain, chest
pain and bleeding from nose and gum.
 Complications :
1. Hypoxemia
2. Multiple organ dysfunction
3. Secondary bacterial and fungal infections

26. Diagnosis
• Nasopharyngeal aspirate/wash
• Nasopharyngeal / oropharyngeal
/throat swab
• Paired serum
• Immuno fluorescent assay (IFA)
• Viral culture
• RT-PCR

27. Management
• General and supportive treatment
• Hospitalize and isolate
• Monitor vital signs
• Maintain ABC
• Maintain hydration, electrolyte and nutrition
• Oxygen
• Fever - Paracetamol

28. Treatment
• Oseltamivir – 75mg BD for 5 days
• After discharge – infection control
precautions – 7 days
• For children less than 12 years –
21 days

29. Chemoprophylaxis
• Neuraminidase inhibitors :
A. Oseltamivir
B. Amantadine derivatives
C. Amantadine and Rimantadine
• Above 1 year :
A. 5 mg/kg/ day (max 150 mg) in two divided
doses – up to 9 years
B. Above that 100 mg bd daily 5- 8 weeks

30. Prevention and control
• Early detection and management
• Containment of transmission
• Decrease social disruption and economic loss
 What if human to human transmission occurs???
Social distancing – closure of schools and other
institutions – avoid social gathering
If large geographical area involved – restriction of
travel and trading

31. Prevention and control
 What if a human case suspected???
Samples – with in 72 hours of illness – within
24 hours to laboratory
Chemoprophylaxis
 What if human case is confirmed???
Isolation of case in a designated hospital
Chemoprophylaxis for contacts and health care
workers
Strict infection control policies in Hospital

32. Recommendations
• Cover the nose/mouth when coughing or
sneezing
• Perform hand hygiene if contact respiratory
secretions and contaminated objects
• Put on a surgical mask
• Respiratory hygiene and cough etiquette
• Use tissue paper to contain respiratory
secretions and dispose in the waste receptacle

33. Swine flu
• Swine flu is a respiratory disease caused by
Type A influenza viruses that infect the
respiratory tract of pigs.
• The H1N1 is said to be a new strain of
virus that is mostly a combination of
human influenza, swine and avian.

34. Mode of transmission
• H1N1 virus can generally be spread through
airborne of droplet transmission.
• A person with swine flu can be contagious
when he coughs, sneezes, or produce droplets
that may land on another person’s open
surfaces, such as the eyes, nose, or mouth.
• Improper handling and cooking of pork
products from swine infested with the H1N1
virus can also be a way to get the illness.

36. Symptoms
• The symptoms of swine flu in people are
similar to the symptoms of regular human
flu.
• fever, cough, sore throat, body aches,
runny nose, headache, chills and fatigue.
• Diarrhea and vomiting, but more
manifested by children.
• Rare cases, progression to pneumonia
and respiratory failure, leading to death.

39. Risk factors
• Average age increasingMedian age 12 – 17 for
illness.
• Risk factors contributing to:
• Serious case :
1. Cardiovascular
2. Respiratory
3. Diabetes
4. Cancer
• Severe case :
1. Asthma and other respiratory disease
2. Obesity
3. Pregnancy

40. Diagnosis
• To swine influenza A infection, a respiratory
specimen would generally need to be
collected within the first 4 to 5 days of illness.
• However, some persons, especially children,
may shed virus for 10 days or longer.
• Identification as a swine flu influenza A.
• virus requires sending the specimen to a
hospital laboratory for testing.

41. Prevention
• Follow precautions for seasonal influenza to
control spread of disease.
• Vaccine approved by US FDA.
• Priority for vaccination is :
1. Health care workers / pediatric care givers
2. Pregnant women
3. Schools (staff and students)
4. Under age 65 with risk factors

42. Prevention
• Wash hands regularly.
• Avoid contact with infected
person.
• Always use a face mask
• Keep yourself isolated
from people with
possible symptoms of
flu.
• Avoid visiting places with
higher possibility of
transmission.

43. Treatment
• Oseltamivir (Tamiflu®) or
• zanamivir (Relenza®) for the treatment
and/or prevention of swine flu infection.
• Ayurvedic treatments : Septilin.
• Some vaccines available like
Squalene (Side effects: Autism)

44. Treatment
• Antiviral drugs are prescription medicines
(pills, liquid or an inhaler) that fight against the
flu by keeping flu viruses from reproducing in
your body.
• If you get sick, antiviral drugs can make your
illness milder and make you feel better faster.
They may also prevent serious flu complications.
• For treatment, antiviral drugs work best if
started soon after getting sick (within 2 days of
symptoms).

45. (Severe Acute Respiratory
Syndrome)

46. Introduction
•SARS is a communicable viral
disease caused by corona virus type
4.
•Declared as a “worldwide health
threat.”
•1st new disease of 21st century.

48. Clinical Symptoms
• Fever, chills
• Malaise
• Dry cough
• Sore throat
• Myalagia
• Headache
• Running nose
Soon the patient develops Viral Pneumonia and
ARD, terminally kidney failure.

49. Incubation period
•It lasts for 2 to 7 days based on
single exposure cases or well
defined cases.

50. SARS transmission pattern
•No evidence of transmission before onset of first
symptoms.
•A few cases thought to have transmitted in the early
prodromal period.
•Those who are very ill or experiencing rapid clinical
deterioration, usually during second week of illness,
are the most communicable.
•No evidence of transmission 10 days post-fever
resolution.

51. •Probable Case
1.A suspect case with radiographic
evidence of infiltrates consistent with
pneumonia or respiratory distress
syndrome on chest x-ray.
2.A suspect case with autopsy finding
consistent with the pathology of
respiratory distress syndrome without an
identifiable cause.

52. Next Pandemic?????